The Model 660 Trip Control, part of the 600 series line of instrumentation controls, is designed to monitor and maintain a set level on a measurable variable, such as liquid level, temperature, pressure, flow, etc. A user-provided 4-20mA current loop represents the measurable application. Two trip points, the rising setpoint, and the falling setpoint are field adjustable. They are set by calibrating the DEAD BAND and TRIP adjustments. If the input is between the two setpoints, the relays are de-energized. If the input goes above the rising setpoint, the RISING TRIP relay energizes to provide a tripped condition. This tripped condition will automatically reset when the input falls back below the setpoint. If the input falls below the falling setpoint the FALLING TRIP relay energizes to provide a tripped condition. The tripped condition resets when the input rises back above the setpoint. The Model 660 has top-mounted LEDs for status indication. Individual RISING TRIP or FALLING TRIP LEDs turn ON in a tripped condition. The INPUT LOOP ERROR LED turns ON if the input is outside the 4-20mA range. A Time Mark Model 650 Loop Power Supply (or equivalent) is required to provide DC operating voltage. A Time Mark Model 672-15 Pressure Transducer (or equivalent) is required to provide the input signal.